How to Tell Possums and Rats Apart by Sound

The single most useful sound-based distinction is the weight of the movement. Possums — particularly Common Brushtail Possums — are relatively heavy animals. Their movement through a roof space tends to sound deliberate: heavy walking, thumping and rolling, as though a small but solid animal is moving around above you.

Rodents are lighter and faster. Rats and mice produce scurrying, scratching and rapid running sounds. The movement is quick and light rather than heavy and deliberate. If what you're hearing sounds fast and fleeting, that leans toward rodents; if it sounds slow and heavy, that leans toward a possum.

Possums are nocturnal and follow a relatively predictable pattern. They typically wake around dusk, leave their shelter between dusk and approximately 11pm — most commonly around 7pm to 9pm — and return to shelter in the early hours of the morning, roughly 3am to 6am. They sleep during the day.

Rodents are less predictable. They can be active at any time, and their activity does not follow the same day–night rhythm. If you're hearing noise during the middle of the day as readily as at night, that pattern leans away from possums and toward rodents — though it is not conclusive on its own.

Where the noise is loudest is not necessarily where the animal is entering. Sound travels through roof spaces and can be misleading about the actual location of activity. A possum may be moving through one section of the roof while its entry point is in another.

Rodents, being smaller, can access tighter cavities — wall voids, subfloor areas and spaces between fixtures — so their sounds can come from locations where a possum could not fit. Hearing scratching from inside a wall, rather than from the ceiling, is more consistent with rodents than with a possum.

The reason we emphasise this so strongly is that the wrong assumption leads to the wrong solution. If you assume possums and arrange possum removal when the cause is actually rodents, the noise continues after the possum is gone — and you've paid for the wrong service.

• Heavy thumping at night could be a possum — or could be a rodent on a surface that amplifies the sound.
• Light scratching could be rodents — or could be a young possum, or a bird, or an electrical issue.
• Daytime noise rules out possums as the sole cause — but rodents and birds can share the same roof space.

A specialist inspection combines your observations — what you've heard, when and where — with physical evidence found in the roof: droppings, damage, runs, nesting material and entry points. The building tells the real story.

Before you book, it helps to note down what you've been experiencing. The more evidence you can provide, the more efficient the diagnosis:

• What does the noise sound like — thumping, scratching, scurrying, gnawing?
• When do you hear it — early evening, late at night, early morning, during the day?
• Where does it seem to come from — ceiling, wall cavity, particular side of the house?
• Have you seen any animal on the roof, near the eaves, or in the garden at night?
• Have you noticed droppings, a smell, or damage to wiring or stored items?

You don't need to know the answer. You don't even need to have formed a suspicion. Noting what you've experienced is enough — the inspection does the rest.